xref: /linux/drivers/acpi/acpica/evhandler.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
1 /******************************************************************************
2  *
3  * Module Name: evhandler - Support for Address Space handlers
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acevents.h"
47 #include "acnamesp.h"
48 #include "acinterp.h"
49 
50 #define _COMPONENT          ACPI_EVENTS
51 ACPI_MODULE_NAME("evhandler")
52 
53 /* Local prototypes */
54 static acpi_status
55 acpi_ev_install_handler(acpi_handle obj_handle,
56 			u32 level, void *context, void **return_value);
57 
58 /* These are the address spaces that will get default handlers */
59 
60 u8 acpi_gbl_default_address_spaces[ACPI_NUM_DEFAULT_SPACES] = {
61 	ACPI_ADR_SPACE_SYSTEM_MEMORY,
62 	ACPI_ADR_SPACE_SYSTEM_IO,
63 	ACPI_ADR_SPACE_PCI_CONFIG,
64 	ACPI_ADR_SPACE_DATA_TABLE
65 };
66 
67 /*******************************************************************************
68  *
69  * FUNCTION:    acpi_ev_install_region_handlers
70  *
71  * PARAMETERS:  None
72  *
73  * RETURN:      Status
74  *
75  * DESCRIPTION: Installs the core subsystem default address space handlers.
76  *
77  ******************************************************************************/
78 
79 acpi_status acpi_ev_install_region_handlers(void)
80 {
81 	acpi_status status;
82 	u32 i;
83 
84 	ACPI_FUNCTION_TRACE(ev_install_region_handlers);
85 
86 	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
87 	if (ACPI_FAILURE(status)) {
88 		return_ACPI_STATUS(status);
89 	}
90 
91 	/*
92 	 * All address spaces (PCI Config, EC, SMBus) are scope dependent and
93 	 * registration must occur for a specific device.
94 	 *
95 	 * In the case of the system memory and IO address spaces there is
96 	 * currently no device associated with the address space. For these we
97 	 * use the root.
98 	 *
99 	 * We install the default PCI config space handler at the root so that
100 	 * this space is immediately available even though the we have not
101 	 * enumerated all the PCI Root Buses yet. This is to conform to the ACPI
102 	 * specification which states that the PCI config space must be always
103 	 * available -- even though we are nowhere near ready to find the PCI root
104 	 * buses at this point.
105 	 *
106 	 * NOTE: We ignore AE_ALREADY_EXISTS because this means that a handler
107 	 * has already been installed (via acpi_install_address_space_handler).
108 	 * Similar for AE_SAME_HANDLER.
109 	 */
110 	for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
111 		status = acpi_ev_install_space_handler(acpi_gbl_root_node,
112 						       acpi_gbl_default_address_spaces
113 						       [i],
114 						       ACPI_DEFAULT_HANDLER,
115 						       NULL, NULL);
116 		switch (status) {
117 		case AE_OK:
118 		case AE_SAME_HANDLER:
119 		case AE_ALREADY_EXISTS:
120 
121 			/* These exceptions are all OK */
122 
123 			status = AE_OK;
124 			break;
125 
126 		default:
127 
128 			goto unlock_and_exit;
129 		}
130 	}
131 
132 unlock_and_exit:
133 	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
134 	return_ACPI_STATUS(status);
135 }
136 
137 /*******************************************************************************
138  *
139  * FUNCTION:    acpi_ev_has_default_handler
140  *
141  * PARAMETERS:  node                - Namespace node for the device
142  *              space_id            - The address space ID
143  *
144  * RETURN:      TRUE if default handler is installed, FALSE otherwise
145  *
146  * DESCRIPTION: Check if the default handler is installed for the requested
147  *              space ID.
148  *
149  ******************************************************************************/
150 
151 u8
152 acpi_ev_has_default_handler(struct acpi_namespace_node *node,
153 			    acpi_adr_space_type space_id)
154 {
155 	union acpi_operand_object *obj_desc;
156 	union acpi_operand_object *handler_obj;
157 
158 	/* Must have an existing internal object */
159 
160 	obj_desc = acpi_ns_get_attached_object(node);
161 	if (obj_desc) {
162 		handler_obj = obj_desc->common_notify.handler;
163 
164 		/* Walk the linked list of handlers for this object */
165 
166 		while (handler_obj) {
167 			if (handler_obj->address_space.space_id == space_id) {
168 				if (handler_obj->address_space.handler_flags &
169 				    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED) {
170 					return (TRUE);
171 				}
172 			}
173 
174 			handler_obj = handler_obj->address_space.next;
175 		}
176 	}
177 
178 	return (FALSE);
179 }
180 
181 /*******************************************************************************
182  *
183  * FUNCTION:    acpi_ev_install_handler
184  *
185  * PARAMETERS:  walk_namespace callback
186  *
187  * DESCRIPTION: This routine installs an address handler into objects that are
188  *              of type Region or Device.
189  *
190  *              If the Object is a Device, and the device has a handler of
191  *              the same type then the search is terminated in that branch.
192  *
193  *              This is because the existing handler is closer in proximity
194  *              to any more regions than the one we are trying to install.
195  *
196  ******************************************************************************/
197 
198 static acpi_status
199 acpi_ev_install_handler(acpi_handle obj_handle,
200 			u32 level, void *context, void **return_value)
201 {
202 	union acpi_operand_object *handler_obj;
203 	union acpi_operand_object *next_handler_obj;
204 	union acpi_operand_object *obj_desc;
205 	struct acpi_namespace_node *node;
206 	acpi_status status;
207 
208 	ACPI_FUNCTION_NAME(ev_install_handler);
209 
210 	handler_obj = (union acpi_operand_object *)context;
211 
212 	/* Parameter validation */
213 
214 	if (!handler_obj) {
215 		return (AE_OK);
216 	}
217 
218 	/* Convert and validate the device handle */
219 
220 	node = acpi_ns_validate_handle(obj_handle);
221 	if (!node) {
222 		return (AE_BAD_PARAMETER);
223 	}
224 
225 	/*
226 	 * We only care about regions and objects that are allowed to have
227 	 * address space handlers
228 	 */
229 	if ((node->type != ACPI_TYPE_DEVICE) &&
230 	    (node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
231 		return (AE_OK);
232 	}
233 
234 	/* Check for an existing internal object */
235 
236 	obj_desc = acpi_ns_get_attached_object(node);
237 	if (!obj_desc) {
238 
239 		/* No object, just exit */
240 
241 		return (AE_OK);
242 	}
243 
244 	/* Devices are handled different than regions */
245 
246 	if (obj_desc->common.type == ACPI_TYPE_DEVICE) {
247 
248 		/* Check if this Device already has a handler for this address space */
249 
250 		next_handler_obj =
251 		    acpi_ev_find_region_handler(handler_obj->address_space.
252 						space_id,
253 						obj_desc->common_notify.
254 						handler);
255 		if (next_handler_obj) {
256 
257 			/* Found a handler, is it for the same address space? */
258 
259 			ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
260 					  "Found handler for region [%s] in device %p(%p) handler %p\n",
261 					  acpi_ut_get_region_name(handler_obj->
262 								  address_space.
263 								  space_id),
264 					  obj_desc, next_handler_obj,
265 					  handler_obj));
266 
267 			/*
268 			 * Since the object we found it on was a device, then it means
269 			 * that someone has already installed a handler for the branch
270 			 * of the namespace from this device on. Just bail out telling
271 			 * the walk routine to not traverse this branch. This preserves
272 			 * the scoping rule for handlers.
273 			 */
274 			return (AE_CTRL_DEPTH);
275 		}
276 
277 		/*
278 		 * As long as the device didn't have a handler for this space we
279 		 * don't care about it. We just ignore it and proceed.
280 		 */
281 		return (AE_OK);
282 	}
283 
284 	/* Object is a Region */
285 
286 	if (obj_desc->region.space_id != handler_obj->address_space.space_id) {
287 
288 		/* This region is for a different address space, just ignore it */
289 
290 		return (AE_OK);
291 	}
292 
293 	/*
294 	 * Now we have a region and it is for the handler's address space type.
295 	 *
296 	 * First disconnect region for any previous handler (if any)
297 	 */
298 	acpi_ev_detach_region(obj_desc, FALSE);
299 
300 	/* Connect the region to the new handler */
301 
302 	status = acpi_ev_attach_region(handler_obj, obj_desc, FALSE);
303 	return (status);
304 }
305 
306 /*******************************************************************************
307  *
308  * FUNCTION:    acpi_ev_find_region_handler
309  *
310  * PARAMETERS:  space_id        - The address space ID
311  *              handler_obj     - Head of the handler object list
312  *
313  * RETURN:      Matching handler object. NULL if space ID not matched
314  *
315  * DESCRIPTION: Search a handler object list for a match on the address
316  *              space ID.
317  *
318  ******************************************************************************/
319 
320 union acpi_operand_object *acpi_ev_find_region_handler(acpi_adr_space_type
321 						       space_id,
322 						       union acpi_operand_object
323 						       *handler_obj)
324 {
325 
326 	/* Walk the handler list for this device */
327 
328 	while (handler_obj) {
329 
330 		/* Same space_id indicates a handler is installed */
331 
332 		if (handler_obj->address_space.space_id == space_id) {
333 			return (handler_obj);
334 		}
335 
336 		/* Next handler object */
337 
338 		handler_obj = handler_obj->address_space.next;
339 	}
340 
341 	return (NULL);
342 }
343 
344 /*******************************************************************************
345  *
346  * FUNCTION:    acpi_ev_install_space_handler
347  *
348  * PARAMETERS:  node            - Namespace node for the device
349  *              space_id        - The address space ID
350  *              handler         - Address of the handler
351  *              setup           - Address of the setup function
352  *              context         - Value passed to the handler on each access
353  *
354  * RETURN:      Status
355  *
356  * DESCRIPTION: Install a handler for all op_regions of a given space_id.
357  *              Assumes namespace is locked
358  *
359  ******************************************************************************/
360 
361 acpi_status
362 acpi_ev_install_space_handler(struct acpi_namespace_node * node,
363 			      acpi_adr_space_type space_id,
364 			      acpi_adr_space_handler handler,
365 			      acpi_adr_space_setup setup, void *context)
366 {
367 	union acpi_operand_object *obj_desc;
368 	union acpi_operand_object *handler_obj;
369 	acpi_status status = AE_OK;
370 	acpi_object_type type;
371 	u8 flags = 0;
372 
373 	ACPI_FUNCTION_TRACE(ev_install_space_handler);
374 
375 	/*
376 	 * This registration is valid for only the types below and the root.
377 	 * The root node is where the default handlers get installed.
378 	 */
379 	if ((node->type != ACPI_TYPE_DEVICE) &&
380 	    (node->type != ACPI_TYPE_PROCESSOR) &&
381 	    (node->type != ACPI_TYPE_THERMAL) && (node != acpi_gbl_root_node)) {
382 		status = AE_BAD_PARAMETER;
383 		goto unlock_and_exit;
384 	}
385 
386 	if (handler == ACPI_DEFAULT_HANDLER) {
387 		flags = ACPI_ADDR_HANDLER_DEFAULT_INSTALLED;
388 
389 		switch (space_id) {
390 		case ACPI_ADR_SPACE_SYSTEM_MEMORY:
391 
392 			handler = acpi_ex_system_memory_space_handler;
393 			setup = acpi_ev_system_memory_region_setup;
394 			break;
395 
396 		case ACPI_ADR_SPACE_SYSTEM_IO:
397 
398 			handler = acpi_ex_system_io_space_handler;
399 			setup = acpi_ev_io_space_region_setup;
400 			break;
401 
402 		case ACPI_ADR_SPACE_PCI_CONFIG:
403 
404 			handler = acpi_ex_pci_config_space_handler;
405 			setup = acpi_ev_pci_config_region_setup;
406 			break;
407 
408 		case ACPI_ADR_SPACE_CMOS:
409 
410 			handler = acpi_ex_cmos_space_handler;
411 			setup = acpi_ev_cmos_region_setup;
412 			break;
413 
414 		case ACPI_ADR_SPACE_PCI_BAR_TARGET:
415 
416 			handler = acpi_ex_pci_bar_space_handler;
417 			setup = acpi_ev_pci_bar_region_setup;
418 			break;
419 
420 		case ACPI_ADR_SPACE_DATA_TABLE:
421 
422 			handler = acpi_ex_data_table_space_handler;
423 			setup = NULL;
424 			break;
425 
426 		default:
427 
428 			status = AE_BAD_PARAMETER;
429 			goto unlock_and_exit;
430 		}
431 	}
432 
433 	/* If the caller hasn't specified a setup routine, use the default */
434 
435 	if (!setup) {
436 		setup = acpi_ev_default_region_setup;
437 	}
438 
439 	/* Check for an existing internal object */
440 
441 	obj_desc = acpi_ns_get_attached_object(node);
442 	if (obj_desc) {
443 		/*
444 		 * The attached device object already exists. Now make sure
445 		 * the handler is not already installed.
446 		 */
447 		handler_obj = acpi_ev_find_region_handler(space_id,
448 							  obj_desc->
449 							  common_notify.
450 							  handler);
451 
452 		if (handler_obj) {
453 			if (handler_obj->address_space.handler == handler) {
454 				/*
455 				 * It is (relatively) OK to attempt to install the SAME
456 				 * handler twice. This can easily happen with the
457 				 * PCI_Config space.
458 				 */
459 				status = AE_SAME_HANDLER;
460 				goto unlock_and_exit;
461 			} else {
462 				/* A handler is already installed */
463 
464 				status = AE_ALREADY_EXISTS;
465 			}
466 
467 			goto unlock_and_exit;
468 		}
469 	} else {
470 		ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
471 				  "Creating object on Device %p while installing handler\n",
472 				  node));
473 
474 		/* obj_desc does not exist, create one */
475 
476 		if (node->type == ACPI_TYPE_ANY) {
477 			type = ACPI_TYPE_DEVICE;
478 		} else {
479 			type = node->type;
480 		}
481 
482 		obj_desc = acpi_ut_create_internal_object(type);
483 		if (!obj_desc) {
484 			status = AE_NO_MEMORY;
485 			goto unlock_and_exit;
486 		}
487 
488 		/* Init new descriptor */
489 
490 		obj_desc->common.type = (u8)type;
491 
492 		/* Attach the new object to the Node */
493 
494 		status = acpi_ns_attach_object(node, obj_desc, type);
495 
496 		/* Remove local reference to the object */
497 
498 		acpi_ut_remove_reference(obj_desc);
499 
500 		if (ACPI_FAILURE(status)) {
501 			goto unlock_and_exit;
502 		}
503 	}
504 
505 	ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
506 			  "Installing address handler for region %s(%X) "
507 			  "on Device %4.4s %p(%p)\n",
508 			  acpi_ut_get_region_name(space_id), space_id,
509 			  acpi_ut_get_node_name(node), node, obj_desc));
510 
511 	/*
512 	 * Install the handler
513 	 *
514 	 * At this point there is no existing handler. Just allocate the object
515 	 * for the handler and link it into the list.
516 	 */
517 	handler_obj =
518 	    acpi_ut_create_internal_object(ACPI_TYPE_LOCAL_ADDRESS_HANDLER);
519 	if (!handler_obj) {
520 		status = AE_NO_MEMORY;
521 		goto unlock_and_exit;
522 	}
523 
524 	/* Init handler obj */
525 
526 	handler_obj->address_space.space_id = (u8)space_id;
527 	handler_obj->address_space.handler_flags = flags;
528 	handler_obj->address_space.region_list = NULL;
529 	handler_obj->address_space.node = node;
530 	handler_obj->address_space.handler = handler;
531 	handler_obj->address_space.context = context;
532 	handler_obj->address_space.setup = setup;
533 
534 	/* Install at head of Device.address_space list */
535 
536 	handler_obj->address_space.next = obj_desc->common_notify.handler;
537 
538 	/*
539 	 * The Device object is the first reference on the handler_obj.
540 	 * Each region that uses the handler adds a reference.
541 	 */
542 	obj_desc->common_notify.handler = handler_obj;
543 
544 	/*
545 	 * Walk the namespace finding all of the regions this handler will
546 	 * manage.
547 	 *
548 	 * Start at the device and search the branch toward the leaf nodes
549 	 * until either the leaf is encountered or a device is detected that
550 	 * has an address handler of the same type.
551 	 *
552 	 * In either case, back up and search down the remainder of the branch
553 	 */
554 	status = acpi_ns_walk_namespace(ACPI_TYPE_ANY, node,
555 					ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
556 					acpi_ev_install_handler, NULL,
557 					handler_obj, NULL);
558 
559 unlock_and_exit:
560 	return_ACPI_STATUS(status);
561 }
562